Google Scholar is able to look at the bibliographies of articles and books. This allows it to connect you to more recent items that have cited something.
First, connect Google Scholar to the Walden Library. This will allow you to connect directly to full text in the library.
Then locate the original Barr & Tagg article in Google Scholar. A search for the author names and article title should be enough.
Click the Cited by link at the bottom of the Google Scholar entry. The screen shot above shows that 2118 items have cited Barr and Tagg.
This will take you to a list of all of those items. Click the Find at Walden link in the right column to go to the full text in the library. This link will be available for only some of the items in Google Scholar.
When an item is cited within an article, you will typically see the authors' last names used for the in-text citation and the full title in the references. This means that you can look for those things in an all text search of a library database.
On the library website, click the blue Articles by Topic button.
Select Education from the list of subjects.
Enter the author name(s) into one search box. Change the Select a Field (optional) dropdown to TX All Text.
Enter the article title into another search box. Again change the Select a Field (optional) dropdown to TX All Text.
Click the link to the full text of one of your results. You can confirm that it has cited the Barr & Tagg article by checking the references at the end of the article. Read or skim the article to find the exact location that the authors discuss Barr & Tagg.